provides physiologic system to supply nutrients to the nervous system
remove metabolic wastes
produce a mechanical barrier to cushion the brain and spinal cord against trauma
the layer that lines the spinal cord and brain
meninges
3 layers of the meninges
dura mater
arachnoid
pia mater
outmost layer of the meninges that lines the skull and verterbral canal
dura mater
a filamentous(spider-like) inner membrane
the middle lining of the meninges
arachnoid
a thin membrane lining the surfaces of the brain and spinal cord
pia mater
where is CSF produced?
choroid plexuses of the 2 lumbar ventricles and the 3rd and 4th ventricles
A. Choroid Plexus of Lateral Ventricle
B. Cerebrum
C. Choroid Plexus of Third Ventricle
D. Subarachnoid Space
E. Arachnoid villus/ granulation
F. Pia Mater
G. Arachnoid
H. Dura Mater
I. Cerebellum
J. Choroid Plexus of Fourth Ventricle
K. Spinal Cord
how much CSF do adults produce?
20mL/hour
the hollow space between the arachnoid and pia mater where CSF flows
subarachnoid space
what is the amount of CSF maintained in adults?
in children?
adults 90-150 mL
children 10-60 mL
its function is to reabsorb CSF at a rate equal to its production
arachnoid granulation/villae
they function as one-way valves that respond to pressure within the CNS and prevent reflux of the fluid
arachnoid granules/villae
they are capillary networks that form the CSF from plasma by mechanisms of selective filtration under hydrostatic pressure and active transport secretion
Choroid Plexuses
True or False
the chemical composition of the CSF does not resemble an ultrafiltrate of plasma
True
the tight-fitting structure of the endothelial cells in the choroid plexuses that prevent chemicals, leukocytes, proteins to enter the CSF
** Why is it tight fit? as compared to those spread throughout the body?
blood-brain barrier
those spread throughout the body are loose to allow passage of soluble nutrients and wastes. this barrier was formed to prevent passage
how is CSF routinely collected?
lumbar puncture between the 3rd 4th and 5th lumbar vertebrae
What is the proper intracranial pressure before lumbar puncture?
in how many bottles/tubes is csf collected?
and to what type of tests does each tube correspond to?
3 bottles
Tube 1 - Chemical and Serologic
Tube 2 - Microbiology
Tube 3 - Cell Count
What do you do with excess CSF fluid after all tests have been performed?
Freeze until further use, or until it is certain that there is no more use for it
How are CSF tubes maintained if it cannot be tested at once?
Tube 1 (Chem and Sero) - frozen
Tube 2 (Microbio) - Room Temp
Tube 3 (Hema) - Refrigerated
Describe Each CSF Tube
1 - Crystal Clear (normal)
2 - Xanthochromic
3 - Hemolyzed
4 - Cloudy
term used to describe CSF supernatant this pink, orange, or yellow
xanthochromia
What causes the pink, orange, or yellow color of the CSF?
Pink - very slight amount of oxyhemoglobin
Orange - heavy hemolysis
Yellow - Conversion of Oxyhemoglobin to unconjugated bilirubin
How do you differentiate a traumatic tap from a cerebral hemorrhage?
Traumatic tap - heavy red at Tube 1
Cerebral Hemorrhage - even distribution throughout the 3 specimen
To what disease is a classic web-like pellicle associated with which can be seen after overnight refrigeration of the CSF?
Tubercular Meningitis
Do all bloody CSF clot?
No, only when cayse by traumatic tap. an intracranial hemorrhage won't have enough fibrinogen to cause the clot
In the CSF, what does the microscopic finding of macrophages containing ingested RBCs or hemosiderin granules indicative of?
Intracranial hemorrhage
What type of cell count is performed in CSF?
leukocyte count (WBC)
Will a CSF specimen produce accurate cell count if it is left to stand for more than 2 hours at room temp?
no, WBC and RBC begin to lyse within 1 hour and 40% of the wbcs disintegrate after 2 hours
it should be refrigerated if the cell count can not be done at once
A - Meningitis
B - Meningitis
C - Protein
D - Hemorrhage
E - Traumatic Tap
F - Hemoglobin
G - Bilirubin
H - Carotene
I - Protein
J - Meningeal melanosarcoma
K - Tubercular meningitis
What is the normal amount of WBC found in the CSF of adults?
0-5 WBC/uL
What cells are normally found in the csf of children?
30 mononuclear cells/uL
What is the diluting fluid used for CSF total cell count?
Normal Saline
Diluting fluid used for CSF that lyses rbc
3% glacial acetic acid
Stain used for CSF WBC count to differentiate neutrophils from mononuclear cells
Methylene Blue
what are the cells normally found in the CSF?
lymphocytes and monocytes
term used for the presence of increased numbers of normal cells in CSF
pleocytosis
A. Viral, Tubercular, and Fungal Meningitis
B. Multiple Sclerosis
C. Bacterial Meningitis
D. Early cases of viral, tubuercular, and fungal meningitis
E. Cerebral Hemorrhage
F. Viral, Tubercular, and Fungal Meningitis
G. Multiple Sclerosis
H. RBCs in spinal fluid
I. Acute Leukemia
J. Disseminated lymphomas
K. Multiple Sclerosis
L. Lymphocyte Reactions
M. Metastatic carcinomas
N. Primary CNS carcinoma
What type of WBCs found in the CSF are increased in cases of HIV or AIDS?
lymphocytes
Type of WBC that is increased in association with parasitic infections, fungal infections
Eosinophils
most frequently performed chemical test on CSF
protein determination
normal value of protein in CSF
15-45 mg/dL
2 most routinely used techniques for measuring total CSF protein
turbidity production (nephelometry)
dye-binding ability
it is detected by electrophoresis which represent inflammation within the CNS
oligoclonal bands
its presence in the CSF may be indicative of recent destruction of the myelin sheath
myelin basic protein
normal value of glucose in CSF
60-70% of plasma glucose
in CSF
low glucose + high neutrophils = a
low glucose + high lympho = b
normal glucose + high lympho = c
a. bacterial meningitis
b. tubercular meningitis
c. viral meningitis
>35mg/dL of CSF Lactate = a
<25 mg/dL of CSF Lactate = b
a. bacterial meningitis
b. viral meningitis
the result of any condition that decreases flow of oxygen to the tissues in CNS
elevated CSF lactate levels
A. Neutrophils present
B. Lymphocytes Present
C. Marked Protein Elevation
D. Moderate Protein Elevation
E. Markedly Decreased Glucose Level
F. Decreased Glucose Level
G. Normal to Decreased Glucose Level
H. Lactate Level >35mg/dL
I. Lactate Level >25mg/dL
J. Lactate Level >25mg/dL
K. Pellicle Formation
L. Positive India Ink with Cryptococcus neoformans
M. Positive Gram stain and bacterial Ag tests
N. Positive immunologic test for C. neoformans
What is formed as a means of ridding ammonia from CNS?
glutamine
normal concentration of glutamine in the CSF
8-18mg/dL
in what syndrome do most children have elevated CSF glutamine levels?
Reye syndrome
formation of bacteria in culture after 6 weeks with CSF Specimen indicates what type of meningitis?
tubercular meningitis
at what level of glutamine is the disturbance of consciousness associated with?
>35 mg/dL
this test is taken alongside with CSF gram stain and culture, due to the 10% chance of the GS and CS being negative even if there is infection
Blood Culture
4 types of bacteria frequently encountered in adult bacterial meningitis
2 bacteria frequently encountered in newborn bacterial meningitidis
Streptococcus agalactiae (gram pos cocci)
Listeria monocytogenes (gram pos rods)
these tests are not routinely performed unless tubercular meningitidis is suspected
acid-fast or fluorescent Ab stains
What is more commonly found in CSF as a complication of AIDS?
Cryptococcus meningitidis
a more sensitive method than india ink
latex agglutination tests
Usual cause of false positive immunologic tests of Cryptococcus in CSF
Rheumatoid factor
what does the serologic testing of CSF detect?
presence of neurosyphilis
test recommended by the CDC for the diagnosis of neurosyphilis
VDRL
The functions of the CSF include all of the following except:
C.
The CSF flows through the:
C.
Substances present in the CSF are contolled by the:
A.
The CSF tube labeled 3 is sent to:
A.
The CSF tube that should be refrigerated is:
B.
Place the appropriate letter in front of the statement that best describes CSF specimens in these two conditions:
A. Traumatic tap B. Intracranial hemorrhage
_____Even distribution of blood in all tubes
_____Xanthochromic supernatant
_____Concentration of blood in tube 1 is greaterthan in tube 3
_____Specimen contains clots
B
B
A
A
The presence of xanthochromia can be caused by all of the following except:
B.
A web-like pellicle in a refrigerated CSF specimen is indicative of:
C.
Given the following information, calculate the CSF WBC count: cells counted, 80; dilution, 1:10; large Neubauer squares counted, 10.
A.
A CSF WBC count is diluted with:
B.
A total CSF cell count on a clear fluid should be:
A.
The purpose of adding albumin to CSF before cytocentrifugation is to:
D.
The primary concern when pleocytosis of neutrophils and lymphocytes is found in the CSF is:
A.
Neutrophils with pyknotic nuclei may be mistaken for:
A.
The presence of which of the following cells is increased when a CNS shunt malfunctions?
C.
Macrophages appear in the CSF following:
D.
Nucleated RBCs are seen in the CSF as a result of:
D.
Following a CNS diagnostic procedure, which of the following might be seen in the CSF?
D.
Hemosiderin granules and hematoidin crystals are seen in:
A.
Myeloblasts are seen in the CSF:
D.
Cells resembling large and small lymphocytes with cleaved nuclei represent:
B.
The normal value of CSF protein is:
C.
CSF can be differentiated from plasma by the presenceof:
A.
In plasma, the second most prevalent protein is IgG;in CSF, the second most prevalent protein is:
D.
Elevated CSF protein values can be caused by all of the following except:
C.
The integrity of the blood-brain barrier is measured using the:
D.
The finding of oligoclonal bands in the CSF and not in the serum is seen with:
D.
A CSF glucose of 15 mg/dL, WBC count of 5000, 90% neutrophils, and protein of 80 mg/dL is suggestive of:
A.
A patient with a blood glucose of 120 mg/dL wouldhave a normal CSF glucose of:
C.
CSF lactate will be more consistantly decreased in:
B.
Measurement of which of the following can be replaced by CSF glutamine analysis in children with Reye syndrome?
A.
Prior to performing a Gram stain on CSF, the specimen must be:
B.
All of the following statements are true about cryptoccocal meningitis except:
D.
The test of choice to detect neurosyphilis is the:
